These sweet potato bowls are an easy go-to weeknight dinner: Steam the sweet potatoes while you sauté the mushrooms with spiced ground lamb, quick-pickle fennel and onions, make a simple yogurt sauce, and dinner is ready in about half an hour.

Heat 2 Tbsp. oil in a large skillet over medium-high. Add lamb, cumin, cinnamon, 1 tsp. pepper, and ½ tsp. salt and press into an even layer. Cook, undisturbed, until well browned on the bottom, about 4 minutes. Break up into pieces with a spatula and continue to cook, stirring occasionally, until browned, 1–2 minutes. Push mixture to one side of skillet and add mushrooms in an even layer; season with salt. Cook, undisturbed, until beginning to brown and soften, 3 minutes, then stir together with lamb mixture. Continue to cook, stirring occasionally, until mushrooms are golden brown, about 2 minutes more.

Divide potato halves between bowls and mash slightly with a fork. Top with yogurt sauce and mushroom mixture. Lift fennel and onion out of vinegar with your hands and scatter over bowls; discard vinegar. Top with mint, fennel fronds (if using), and pepper.